The present invention relates to a telephone switch from which only originating calls are made. The switch can be considered as being a slave switch to a superordinate or master switch which functions as an intermediary for incoming traffic to users in the slave switch. The directory numbers of the users of the slave switch belong to the number series of the master switch, and consequently an incoming call is directed to the master switch. Instead of connecting the incoming call to the slave switch, the master switch performs a by-pass signalling procedure to the slave switch, which in response to the by-path signals makes an outgoing call which "meets" the incoming call in the master switch. By by-pass signalling is meant signalling over a signalling path which is separate from the connection path. According to one preferred embodiment of the invention, the slave switch is mobile and permits traffic between a local network and a host network. The local network may be a fixed line network or a business-cordless network, and the host network may be the fixed telephone network or the mobile telephone network.